A man landed on Mars? You must be joking. It ______ be true.
Mount Wutai,_____we visited last month,attracts hundreds of thsousands of vistors every year.
Not able to______city life, Granny decided to go back to the village and live in peace there.
---Many species are now in danger of dying out.----True.Measures should be______to protect them right now.
.It is reported that two schools,_______fell into ruins in the earthquake, are being rebuilt and will be open next term.
Finally, I bought the new book,_____I spent twenty yuan, in the bookstore where a friend of mine is the boss.